Modeling high-speed reacting flows with variable turbulent Prandtl and Schmidt numbers

Abstract

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.

A turbulence model that considers the impact of compressibility effects on turbulence and allows for the calculation of the variable turbulent Prandtl (PrT) and Schmidt (ScT) numbers as part of the solution is presented. The model is based on modeling the slow part of pressure/scalar-gradient correlation depending on characteristic time of scalar variable fluctuations (the ratio of scalar variable variance to its dissipation rate) and on the assumption that the velocity fluctuations directed normal to the streamlines play a key role in turbulent mixing process. For the validation of the code the described numerical procedures are applied to a series of jet flow problems. These include supersonic turbulent jets of variable composition and high-speed chemically reacting coflows.